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Pgtented Aug. 26, 1919.

an no nl'opyi m e. vou'anco AND A.- MEISSNER. HIGH FREQUENCY GENERATORFOR TELEGBAPHY AND TELEPHONY.

APPLICATIQII FILED IMLIJ. 19H.

1,314,101 Patented Aug. 26, 1919.

2 SHEETS-SHEET 2- PATENT OFFICE.

GEORG Von ARGO AND ALEXANDER IEISSNER, OF BERLIN, GERMANY.

HIGH-FREQUENCY GENERATOR FOB TELEGRAPH AND TELEPHONY.

Specification of Letters lfatcnt- Patented Aug. 26, 1919.

Original appflcation filed larch 0, 1914, Serial No. 822,901. Dividedand this application 11ml March 88,

' 1911. Berta! Io. 168,805.

To all whom-it mm concern:

Be it known tliatwe, GEono von Anoo and ALEXANDER -ME18SNER, subjects of,the German and Austrian Emperors, re tively, and both residing atBerlin, ermany, have invented certain new and useful Improvements inHigh-Frequency -Generators for Telegraphy and Telephony, of which thefollowing is a specification.

High f uemy oscillations which have been hereto are used transmittingstations for wireless telegraphyand telephony, have been producedheretofore chiefly by means of sparks or electric arcs. For uitc sometime-attempts have also been ma e to produce currents of such'ehighfrequencies directly in the rotating generators and the advantage was exted to more conveniently and economically generate the necessary largeamount of 'ener for. stations having very languages; e early experimentsin this direction, however, have been unsuccessful, since it has notbeen possible to produce appreciable amounts of en:

ergy in the high frequency generators. So

farus recent experimenters have-succeededin constructing high frequencygenerators yielding appreciable amounts of energy,

they have succeeded only with very expen-- sive machines. Besides,such'machlnes constructedheretofore have shown a number of technicaldisadvantages; the principal of which is that it is possible to vary thewave lengths within wide limits, such as is nee cssary in most intancesin transmittin sta tions, onl by controllin ..th revo ution number 0 themachine. his results, however, in a very uneconomical operation of thegenerator. Mbreover, great diiliculties have been encountered instations attempting to transmit a large amount of energy in such manner,in controlling the high frequency currents for the purpose of produc ingsignals or speech, because it was necessary to directly influence andinterrupt the strong high frequency currents for this purpose.

The means for'overcoming these difiiculties have been disclosed in. ourco-pending.

application, Serial No. 822,901 filed March 6, 1914, patented May 21,1918, No. 1,267,018, from which the present application has beendivided.

The particular object of the invention dis-' closed in the presentapplication is to over comeceu'tain difliculties, encountered heretofore in constructing a suitable generator capable ofasubstantialenergy output at such frequenciesfithat only a few timesnlule generated frequen is tiplication of t necessary in order to obtainthe desi quency at which the energy is radiated by the antenna.

Experiments have proven that itjs possible to obtain an increase offrequency amounting to any desired multiplegoftho fundamental frequency1producedby the generator by means of only a few sets offrequency-changers, such 5&8 are disclosed and described in theircircuit arrangement in the above mentioned parent up llcation.

As has been described and shown t erein, it

The particular novel features ofpur genorator are illustrated more orless diagrammatically in the accompanying drawings in which:

Figure 1 is and rotor.

Fig. 2 is a vertical section of the stator on the line'X-X in Fig. 1.

Figs. 3 and 4 a side elevation of the stator are winding diagrams of thestator winding. After many experiments we have found that a type ofgenerator, havinganair gap, the longitudinal axis of'which extends n thedirection oith'e rotor axis, furnishes the best results. Owing to thisconstruction it is possible to make the air gap very small, which is ofgreat importance on account of the large number of poles. -Besides usina small air gap also has the advantage of mcreasing the output of themachine. The use of an air gap, extending in the direction if the rotoraxis is in contradistinction to i the radially extending air gapsheretofore used in high frequency alter'nators.

The rotor is indicated at 3 in Fig. 1 and consists of a toothed wheel-ofmagnetic maconductor to analternating,

ati field ux.

described later on; Thus high frequency al- I ternating current is notproduced as in ordinary machines by exposin the armature ut to afluctuemanrl er in which this efl'ect is obtairi'ed is shown iii Fig. 2and will be referred to in detail hereinafter. It is of rticularadvantnge to symmetrically divide the whole stator in the middle atright angles to the rotor axis so that two stators of equal dimensionsare obtained which have a common rotor. As shown in Fig. 2 a main solid,substantially cylindrical iron frame 1 curries within, suitably fastenedto it, two laminated stator armature .rings 2. 2', each provided withgrooves 4 (Fig. l) to receive their respective armature windings and 5".Between the two stator rings, which are spaced apart is arranged thefield winding 7, snitably fastened to the frame ring 1. The rotor 3 isomitted in F ig. 2 but assumed to be of .suflicient length to be commonto both '.stutors. When the field winding is ener gized,.the rotor actslike a short, magnetized" rod, whose m etic flux is closed on itsoutsid'ethrough t e two laminated stators and throu h ring'l as shown bythe dotted lines with e arrows. Thus when the rotor turns, the magneticflux in the rotor and stator teeth maintain the same direction at alltimes but varies in intensity in the teeth as the rotor teeth pass thestator teeth. By this variation in flux the alternating currents areinduced in the stator windings.

As shown in Fig. 2 the two stator rings 2 and 2 have continuous wavewinding. In

this figure 5 and 5' represent portions of the windin \Ve have found itbest to arrange both windings electrically in parallel to each other soas to maintain the generator scltinduction, and thus the generatorpotential, which may be produced by resonance within the winding, at alow value. This precaution is all the more necessary since. in highfrequency generators, on account of the large number of poles, theinsulation of the anon-- ture winding is rendered diilicult,conllnu'cdwith machines of ordinary commercial frequency. Fig. 3 shows thisparallel arrangement where 5 and 5 diugrammaticnlly ropresent the twostator windings.

In order to further reduce the insulation dilliculties due to rises inpotential, each stator 2 and 2', in case of generators with large energyoutput, is divided into an equal number of sections as shown in Fig. 4,and the corresponding sections of the two star are in each case arrangedin parallel into inmngroup and the groups thus formed are armnged inseries, preferably with a condenser 8 placed between each group. In Fig.4 four such groups I, II, III, IV, are shown. This arrangementmaterially reduces the equalizing currents which occur in the parallelarrangement of the two armature halves of the entire machine and whichare due to slight unsymmetries in the winding. Moreover the maximumpotential between the entire winding and the stator iron is not greaterthan the potential between an individual grou and the iron.

In case 0 large energy output it is advisable to provide means forconducting cooling water through the stator iron, because the commonlyemployed air cooling pro duces an undesirable air friction at the highspeeds at which machines ofthis character are run. As shown in Figs. 1and 2, tubing 6 and 6", preferably of copper, is led in form of a wavewinding, suitably spaced, through each stator, through which coolingwater is pumped.

Ve claim:

In a radio transmission station of the character described, a highfrequency generator of the inductor type having an air gap thelongitudinal axis of which has the direction of the axis of the rotor,and having a plurality of stators and windin thereon, each statorwinding being divic ed into a plurality of equal sections, thecorresponding sections of all stators being joined into groups' andbeing arranged within each group electrically in parallel to each other,all of said groups being electrically arnnngcd in series, and condensersdisposed

